Hmm.. I don't know anything about alpaca so you'd need to check that with someone else but I have never considered them since I see no purpose in them. I suppose you could eat them but idk any one that does and you're vegetarian anyways. I'm not sure what they would produce that would be beneficial except maybe fiber??? I wouldn't do horses personally but if you have plenty of land they are beautiful creatures and you can ride them although their stuff is expensive and they can be expensive to feed. We are looking at donkeys instead of horses. They live better off pasture, can be ridden, used as draft animals and double as livestock guardians. Goats are amazing. I love them.
They can be eaten although that's not an issue for you. They also provide milk and dairy products. There are plenty of recipes for items such as goat's milk soap as well so there would be numerous things that could be produced and sold from them. Certain breeds can also be fiber animals. They do very well on pasture will little to no supplementation if you use good pasture management. Sheep are another good one like goats. Milk products, fiber, plus meat and furs if they've been killed. They can also do well on pasture.
It is possible to do multi-species livestock grazing on the same land if you want and is often done in paddock style pasturing. Goats and sheep work well together in this way since goats are more browsers (eating up - trees and brush) and sheep are more grazers (eating down - grass, weeds). Chickens can also be run behind the animals in the same paddocks and will eat the bugs that are left behind. This will help with worm and bug infestations as well as the chickens will kill off many of them. If you do get chickens and livestock that's something to consider. The dog I can understand you likely have a pet breed picked out but if you get livestock and don't get donkeys (for livestock protection) then consider LGDs - livestock guardian dogs. Some good breeds for this are Great Pyrenees and Anatolian Shepherds. I've had the Great Pyrenees before and they're awesome dogs although they are large.
Our goal with livestock is to have chickens, rabbits, goats and/or sheep, donkeys (for protection), turkeys, possibly some quail, and bees. There have been discussions about pigs and maybe a small cow but I shut those down pretty quick
If we weren't going for any meat production though then I'd probably do chickens, sheep (or maybe a fiber breed of goat), donkeys, maybe quail, and bees. I'd maybe consider the fiber rabbits as well but I doubt it.